A substrate processing apparatus for performing predetermined processing on a substrate is known as thin film deposition apparatus such as sputtering apparatus and chemical vapor deposition (CVD) apparatus, etching apparatus, surface oxidation apparatus, surface nitridation apparatus, and the like. These substrate processing apparatus comprising an airtight processing chamber in order to process substrates in a predetermined atmosphere. Further, the substrate processing apparatus has often a plurality of processing chambers from the purpose of continuously performing different processing, and increasing productivity. In this description, these substrate processing apparatus having a plurality of processing chambers (process rooms) are collectively referred to as multi-chamber substrate processing apparatus.
One typical type of multi-chamber apparatus is a cluster tool type shown in FIG. 14. This type is configured to circumferentially couple a plurality of vacuum processing chambers 13a, 13b, 13c and a load lock chamber 10 in an airtight condition to a transfer chamber 11 including a robot for transferring substrates (hereinafter refer to as a transfer robot).
After the load lock chamber 10 is evacuated from atmosphere to vacuum, a substrate (not shown) is transferred to the vacuum processing chamber 13a by a transfer robot 12 in the transfer chamber 11. After being processed in the vacuum processing chamber 13a, substrates (not shown) are transferred to a vacuum processing chamber 13b by the transfer robot 12 in the transfer chamber 11. After being processed in the vacuum processing chamber 13b, substrates (not shown) are transferred to the vacuum processing chamber 13c by the transfer robot 12 in the transfer chamber 11. After being processed in the vacuum processing chamber 13c, substrates (not shown) are carried out and return to the load lock chamber 10.
A cluster tool type multi-chamber substrate processing apparatus may have merits of providing a relatively large number of processing chambers with relatively small occupied area. In the above described substrate processing apparatus, a need has arisen for providing more processing chambers with increased complexity and integration in entire processing, request for improvement of productivity and the like as a background.
For example, as processes to be continuously performed under vacuum increase, a number of processing chambers may also be required to be increased accordingly. As the same processes are performed in parallel for improving productivity, more chambers may also be required.
To increase the number of processing chambers in the cluster tool type apparatus, a circumferential length of a central transfer chamber (reference numeral 11 shown in FIG. 14) increases. This increases the size of the transfer chamber, and results in a large operating range of the transfer robot. The large size of the transfer chamber makes an evacuating time longer. Meanwhile, the large operating range of the transfer chamber requires a larger size transfer robot, which causes a problem that the apparatus becomes mechanically complex.
As disclosed in the patent document 1, a mechanism for transferring substrates by an in-line system is considered for avoiding above described problem.
Patent document 1: Japanese Patent Application Laid-Open No. 2005-289556